JP2001036726A - Image processing method, image processing system, and recording medium recording image processing program - Google Patents

Abstract

(57) [Problem] To convert digital image data output from a digital camera into digital image data having the same aspect ratio as a silver halide photograph while suppressing unnaturalness of an image obtained by conversion of an aspect ratio. Convert. SOLUTION: Coordinate conversion processing is performed on all pixels of first digital image data output from a digital camera so that a pixel located farther from a reference pixel set as an important part of an image has a larger coordinate shift amount. Do. As a result, the second digital image data having the same aspect ratio as the silver halide photograph can be obtained while suppressing the unnaturalness of the image due to the conversion. The image processing method includes the steps of: setting a scaling ratio of an image; setting position information of a reference pixel of the image; calculating a pixel movement amount for all pixels of the first digital image data; Moving and compensating for continuity of the converted image data.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image processing method, an image processing system, and a recording medium on which an image processing program is recorded, and in particular, prints digital image data output from a digital camera at an aspect ratio of a silver halide photograph. , An image processing system, and a recording medium on which an image processing program is recorded.

[0002]

2. Description of the Related Art Conventional silver halide photography has an aspect ratio of 1: 1.5, that is, the ratio of the image width in the image vertical direction (image short direction) to the image horizontal direction (image long direction) (when the image is digital data). In the case of, the ratio of the number of pixels in the image vertical direction to the image horizontal direction), and in accordance with this, a photographic printer compatible with silver halide photography has a digital paper having an aspect ratio of 1: 1.5 on print paper. It has a function to print image data.

For example, as a so-called L version, 89 mm long ×
A silver halide photographic print having a width of 127 mm is widely used, and when printing at such a size, a 127 mm width print sheet (hereinafter referred to as 127 mm paper) is usually placed around a predetermined axis. Using a wound roll, pull out the paper 8
Print over a length of 9 mm.

In addition, 89 mm wide print paper (hereinafter, referred to as print paper)
89 mm paper) using a roll wound around a predetermined axis to print a photo over a length of 127 mm in the paper drawing direction, or a 127 mm paper roll and 89 mm depending on the photo printer. In some cases, a roll of millipaper is used selectively.

[0005]

In recent years, not only conventional silver halide photography but also a so-called digital camera has been widely used as an imaging means. A digital camera is a camera that forms an image on a CCD image sensor with a lens and records this as digital image data in a built-in memory or memory card.

In general, the aspect ratio of digital image data of a digital camera is 3: 4, which is different from the aspect ratio of silver halide photography of 1: 1.5. In other words, the silver halide photograph has a slightly longer shape than the image based on the digital image data of the digital camera.

Since digital image data of a digital camera is often processed and stored on a personal computer, data affinity with a display of a personal computer is emphasized rather than silver halide photography. This is because the display standard of the computer has an aspect ratio of 3: 4. For example, the number of pixels defined by the display standard of a personal computer is 480 × 640 pixels in VGA (video graphics allay) and XGA (extended video graphic).
768 × 1024 pixels.

Accordingly, when an image based on digital image data output from a digital camera is to be printed by a conventional photographic printer for silver halide photography, the aspect ratio of the digital image data output from the digital camera corresponds to the photographic printer. Since the aspect ratios of digital image data differ, the following problems occur.

When an entire image of digital image data (aspect ratio: 3: 4) output from a digital camera is to be printed on printer paper corresponding to a silver halide photograph (aspect ratio: 1: 1.5), printing is performed. Since the horizontal direction of the paper is too long, an unprinted white margin portion of the image remains on the left end or the right end of the print paper. Therefore,
If the image of the digital image data output from the digital camera is printed at the same aspect ratio, the use efficiency of the print paper is poor.

On the other hand, in order to put the whole of the digital image data of the digital camera into the entirety of the print paper by giving priority to the use efficiency of the print paper, it is necessary to cut the upper end or the lower end of the digital image data of the digital camera. No. This not only reduces the amount of information of the digital image data that has been recorded, but in some cases, there is a possibility that an important subject may be cut.

However, since the print paper is usually in the form of a roll, the aspect ratio of the print paper is changed by appropriately changing the print width in the roll pull-out direction, and the digital image data of the digital camera is changed. It is not impossible to print the entire image on a print sheet without white margins.

For example, in FIGS. 2A and 2B, a rectangular area surrounded by a thick line is a print area for printing an L plate of 89 mm × 127 mm on 127 mm paper and 89 mm paper, respectively. Is shown.

Here, in order to print the entire image of the digital image data on a print sheet without a white margin while keeping the aspect ratio of the digital image data of the digital camera, the image width of the digital image data must be short in the vertical direction. Printing is performed in the dot area according to the width of the print paper.

Therefore, when printing the entire image on 127 mm paper while keeping the aspect ratio of the digital image data of the digital camera, the print area is as shown in FIG.
As shown in (a), the size is much larger than the size of the L plate.

When the entire image of the digital image data is printed on 89 mm paper while keeping the aspect ratio of the digital image data of the digital camera as it is, the print area is the size of the L plate as shown in FIG. Less than.

The size deviation between the print area and the L plane in the case of FIG. 2B is smaller than that in the case of FIG. 2A. Also,
Theoretically, if the paper width is set to a special size of 118 mm, the digital image data of the digital camera becomes 3:
While maintaining the aspect ratio of 4, it is also possible to obtain a print of the size closest to the L size (88.5 mm × 118 mm).

However, in practice, it is not easy to change the width of the print paper or the print width in the roll pull-out direction even slightly, and the structure of the developing unit, the cutting unit, the transporting unit, etc. of the photographic printer is changed. It is necessary to correspond to the size. Therefore, if the size of the silver halide photographic print is different from the size of the print of the image based on the digital image data of the digital camera, the versatility of the photographic printer is impaired, resulting in a problem that the structure becomes significantly complicated and the cost increases. Furthermore, it is inconvenient for consumers and distributors to handle and store prints.

[0018] Also, by changing the paper width to 89 mm or 118 mm, the print size of the image based on the digital image data of the digital camera can be made somewhat closer to the L size, but the 89 mm paper described above is used. Is not as popular as 127 millimeter paper,
It is necessary to replace the paper roll at the time of switching the printing between the silver halide photograph and the image based on the digital image data of the digital camera.

As a different approach which does not cause such a problem, as shown in FIG. 3, an entire image based on digital image data of a digital camera is previously uniformly enlarged or reduced in the vertical or horizontal direction of the image. In such a case, a method of performing printing after converting digital image data of a digital camera into the same aspect ratio as a silver halide photograph can be considered.

However, when such image processing is performed,
Although the aspect ratio of an image based on digital image data of a digital camera becomes equal to that of a silver halide photograph, the image becomes an unnatural image elongated in any of the vertical and horizontal directions.For example, an image that was originally a circle becomes an ellipse. This leads to problems.

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and has as its object to simply and naturally print digital image data output from a digital camera at the same aspect ratio as a silver halide photograph. An object of the present invention is to provide an image processing method, an image processing system, and a recording medium on which an image processing program is recorded.

[0022]

According to a first aspect of the present invention, there is provided an image processing method comprising: a first digital image data having a first aspect ratio for all pixels of a first digital image data; The second digital image having a second aspect ratio different from the first aspect ratio by performing a coordinate conversion process in which a pixel located at a position farther from the reference pixel of the digital image data has a larger coordinate shift amount. It is characterized by including a coordinate conversion step of obtaining data.

In the above configuration, the coordinate movement amount of a certain pixel means a displacement amount on each coordinate axis in a spatial coordinate system in which pixels are arranged for image formation. Therefore, for example, when pixels are arranged in a two-dimensional orthogonal coordinate system having a vertical axis and a horizontal axis, the closer the pixel is to the reference pixel of the first digital image data, the smaller the coordinate shift amount along the vertical axis and the horizontal axis. Then, as the pixel is farther from the reference pixel, the coordinate movement amount along the vertical axis and the horizontal axis becomes larger.

At this time, if the coordinate movement of the pixel to be subjected to the coordinate conversion processing (hereinafter, referred to as a pixel of interest) is performed along a certain coordinate axis in a direction away from the reference pixel, the first digital image data is If the coordinate transformation process of enlarging the image shown along the coordinate axis is performed, and if the coordinate movement along the coordinate axis is performed in a direction approaching the reference pixel, the image represented by the first digital image data is converted to the coordinate axis. Is performed along the coordinate transformation.

The set of pixels of the first digital image data subjected to the coordinate transformation processing constitutes second digital image data having a second aspect ratio different from that of the first digital image data. is there.

However, if the aspect ratio is transformed by the coordinate transformation process as described above, the image represented by the second digital image data is different from the image represented by the first digital image data. Induces distortion.

Therefore, in the present invention, as already mentioned, the closer to the reference pixel of the first digital image data, the smaller the coordinate shift amount. Which pixel is selected as a reference pixel is arbitrary.For example, if a pixel forming an important subject is selected as a reference pixel, the coordinate movement amount of the pixel forming the important subject becomes an image other than the important subject. Is relatively small as compared with the coordinate movement amount of the pixels constituting the image data, so that deformation or distortion of an important subject can be minimized and digital image data having a desired aspect ratio can be obtained.

Specifically, when the aspect ratio of the first digital image data is larger than the aspect ratio of the second digital image data, for example, the first digital image data having the aspect ratio of 3: 4 When the conversion processing is performed to obtain the second digital image data having the aspect ratio of 1: 1.5, the entire first digital image data is enlarged along the horizontal direction of the image by the coordinate conversion processing. , In the vertical direction of the image.

Conversely, when the aspect ratio of the first digital image data is smaller than the aspect ratio of the second digital image data, for example, the first digital image data having an aspect ratio of 1: 1.5 When performing the conversion process to obtain the second digital image data having the aspect ratio of 3: 4, the entire first digital image data is enlarged along the image vertical direction by the coordinate conversion process, It will shrink along the horizontal direction.

Of course, the coordinate conversion process is not limited to the above. For example, enlargement and reduction in the vertical and horizontal directions of the image may be appropriately combined, and the displacement direction by the coordinate conversion process may be changed to the first digital value. It may be the diagonal direction of the image of the image data. Furthermore, after setting a polar coordinate system to the first digital image data, the polar coordinate system is converted to an elliptical coordinate system to obtain second digital image data having an aspect ratio different from that of the first digital image data. A two-dimensional coordinate conversion process is also included.

Thus, even if the aspect ratio of the first digital image data desired to be output does not match the corresponding second aspect ratio of the output device, the important area of the first digital image data is The second digital image data having the second aspect ratio suitable for output can be obtained by converting the entire first digital image data while suppressing image distortion.

In the above configuration, when the first digital image data is subjected to the enlargement processing, the first digital image data is subjected to the first digital image data before the coordinate conversion.
Pixels adjacent to each other in a grid pattern in the digital image data may not be adjacent to each other in the second digital pixel data after coordinate conversion, and a gap may be generated in the pixel grid. is there.

When the image is reduced, a plurality of pixels located at different positions in the first digital image data before coordinate conversion are regarded as the same pixel in the second digital pixel data after coordinate conversion. It may overlap,
The processing of such an overlapping portion is also optional.

For example, of a plurality of overlapping pixels, a value of a pixel located on the right side in the first digital image data before conversion is adopted as a pixel value of the second digital image data, The pixel thinning process may be performed by adopting the value of the pixel closer to the reference pixel in the first digital image data before conversion as the value of the pixel of the second digital image data.

However, when the image is reduced, the amount of information of the pixels in the first digital image data is reduced. Instead, the second digital image is enlarged by enlarging the first digital image data. A method of obtaining data is preferred.

According to a second aspect of the present invention, there is provided an image processing method according to the first aspect, wherein:
A direction of conversion of the aspect ratio to the second digital image data is determined based on the first digital image data, and a coordinate conversion process is performed such that the more pixels away from the reference pixel along the direction, the larger the coordinate movement amount. It is characterized by performing.

Here, the conversion direction of the aspect ratio is selected to obtain second digital image data having a second aspect ratio different from the first aspect ratio.
One direction for enlarging or reducing the first digital image data.

According to the above configuration, in addition to the operation of the first aspect, the coordinate conversion processing is performed along the conversion direction of the aspect ratio arbitrarily selected in the first digital image data. The more the distance between the target pixel and the straight line that is orthogonal to the pixel and includes the reference pixel, the greater the amount of coordinate movement by the coordinate conversion process.

According to this, in addition to the effect of the first aspect, when the important regions in the first digital image data are distributed in a row like an upright figure, the distribution of the important regions is parallel. Alternatively, by determining the aspect ratio conversion direction in a direction orthogonal to the direction, the image distortion due to the coordinate conversion processing is less unnatural, and a more natural image can be obtained as the second digital image data.

According to a third aspect of the present invention, there is provided an image processing method according to the first or second aspect, wherein the coordinate movement amount is determined based on an enlargement / reduction ratio of the image and the reference pixel and the pixel of interest. Is determined by calculation based only on relative position information with respect to.

According to the above configuration, for example, by appropriately using a function consisting of the scaling ratio of the image and the relative position information between the reference pixel and the pixel of interest, the first digital image data can be located at a position distant from the reference pixel. The coordinate movement amount of the target pixel can be calculated based only on the scaling ratio of the image and the relative position information between the reference pixel and the target pixel so that the coordinate movement amount by the coordinate conversion process becomes larger for a certain target pixel.

Here, the image enlargement / reduction ratio is an enlargement / reduction ratio for obtaining the second digital image data with reference to the first digital image data, and enlarges / reduces the first digital image data. It also includes the concept of the direction to be taken.

More specifically, when the second digital image data having a desired second aspect ratio is obtained by enlarging or reducing the first digital image data in the image vertical direction, the second digital image data Means the aspect ratio of the first digital image data to the aspect ratio of the first digital image data.
When obtaining the second digital image data having a desired second aspect ratio by scaling the digital image data in the horizontal direction of the image, the aspect ratio of the first digital image data and the second digital image data Means the aspect ratio.

In a broad sense, the aspect ratio itself of the second digital image data and the number of pixels arranged in the second digital image data itself are also included in the image scaling ratio. This is because, when the aspect ratio and the number of pixel arrays of the first digital image data are fixed, the scaling ratio of the image is determined based on the aspect ratio and the number of pixel arrays of the second digital image data. This is because it can be uniquely calculated.

On the other hand, the position information of the reference pixel may be a specific numerical value of the coordinates of the reference pixel in the first digital image data, or may be information for uniquely defining the coordinates. As an example of the latter, information such as a pixel having the lightness and chromaticity closest to a specific lightness and chromaticity combination in the first digital image data may be considered.

The enlargement / reduction ratio of the image and the position information of the reference pixel may be set in advance or may be inputted from outside. Further, it may be automatically determined by analyzing the first digital image data as described above.

Thus, in addition to the effect of the first or second aspect, the number of parameters required for the calculation in the coordinate conversion processing is reduced, and the second digital image data having a desired aspect ratio is obtained simply and quickly. be able to.

According to a fourth aspect of the present invention, there is provided an image processing method according to any one of the first to third aspects, wherein the enlargement / reduction ratio of the image and the position information of the reference pixel are determined. It is characterized by including a step of inputting at least one.

According to the above configuration, in addition to the function of any one of the first to third aspects, a parameter used for calculation for performing a coordinate conversion process on the first digital image data is input from outside. Will be. In this case, both the image scaling ratio and the reference pixel position information may be input from outside as necessary and sufficient parameters used in the calculation of the coordinate transformation process, or the image scaling ratio and the reference pixel position information may be input. If one of them has already been set and calculated, only the remaining one may be input. Here, the significance of the enlargement / reduction ratio of the image and the position information of the reference pixel is the same as in claim 3.

As an example in which the image enlargement / reduction ratio and the reference pixel position information are already set, an image having a so-called B5 size aspect ratio is converted into an image having a so-called A5 size aspect ratio. Assuming that the rate has been set to a fixed value in advance, or that an important subject has been shot at the center of the first digital image data,
There is a case where the position of the reference pixel is previously set to a fixed value at the center position of the first digital image data.

Thus, any one of claims 1 to 3
In addition to the effect of the item, the second digital image data having a desired aspect ratio can be obtained by an extremely simple operation of inputting either or both of the image scaling ratio and the reference pixel position information. In addition to this, it is possible to easily change the set values of the image enlargement / reduction ratio and the position information of the reference pixel from outside.

According to a fifth aspect of the present invention, in the image processing method according to any one of the first to fourth aspects, the reference pixel is the first digital image data of the first digital image data. It is characterized in that it is a pixel located in the central area.

According to the above configuration, in addition to the operation of any one of the first to fourth aspects, the reference pixel is located in the central area of the first digital image data. , The image distortion in the central area is suppressed, and the farther from the central area, the greater the image distortion due to the coordinate transformation process.

In practice, the creator of the first digital image data, for example, the photographer of the digital camera, shoots the image so that the main subject, which is an important part of the image, is located in the central area of the first digital image data. It is thought that it is often done.

Therefore, in addition to the effect of any one of the first to fourth aspects, when it is determined in advance that the main image portion is located in the central region of the first digital image data, the coordinate conversion process is performed. In the calculation, without treating the position information of the reference pixel as a variable or inputting from the outside,
A second digital image having a desired second aspect ratio while suppressing image distortion for an important part of the first digital image data.
Digital image data can be obtained.

According to a sixth aspect of the present invention, there is provided an image processing method according to any one of the first to fifth aspects, wherein the first aspect ratio and the second aspect ratio are provided. Is characterized by the aspect ratio of display data of a personal computer, and the other is the aspect ratio of silver halide photography.

According to the above arrangement, in addition to the function of any one of the first to fifth aspects, the first digital image data is used for storing the photographing data of a digital camera, the data for display display of a personal computer, or the data based on the data. In the case where the image data is converted, the second digital image data having the same aspect ratio as the silver halide photograph can be obtained by performing the conversion processing on the entire first digital image data.

Conversely, when the first digital image data is an image having the same aspect ratio as a silver halide photograph, for example, an image obtained by converting a silver halide photograph into a data by a scanner,
By converting the entire first digital image data, it is possible to obtain second digital image data having the same aspect ratio as image data captured by a digital camera or display data of a personal computer.

Thus, any one of claims 1 to 5
In addition to the effects of the item, image data having the same aspect ratio as silver halide photography can be transferred to a digital camera as a natural image or printed with a digital camera dedicated printer, and further, can be displayed on a personal computer display. Can be displayed without margins.

Further, it is possible to print photographing data of a digital camera, display data of a personal computer, and the like using a photographic printer compatible with silver halide photography without unnatural images and unnecessary white borders.

According to a seventh aspect of the present invention, there is provided an image processing method according to any one of the first to sixth aspects, wherein the first aspect ratio and the second aspect ratio are provided. One is 3: 4 and the other is
1: 1.5.

According to the above arrangement, in addition to the function of any one of the first to sixth aspects, when the first digital image data is an image having an aspect ratio of 3: 4, By performing conversion processing on the entire digital image data, it is possible to suppress image distortion around the reference pixel while maintaining 1: 1.
Second digital image data having an aspect ratio of 5 can be obtained.

Specifically, for example, the first digital image data is enlarged 9/8 times in the horizontal direction of the image, or the first digital image data is enlarged.
The second digital image data is obtained by reducing the digital image data at 8/9 times in the vertical direction of the image.

On the contrary, the first digital image data is:
In the case of an image having an aspect ratio of 1.5, the entire first digital image data is converted to convert the entire first digital image data to reduce image distortion around the reference pixel. While suppressing 3:
Second digital image data having an aspect ratio of 4 can be obtained.

Specifically, for example, the first digital image data is enlarged 9/8 times in the vertical direction of the image,
The second digital image data is obtained by reducing the digital image data of the above by 8/9 times in the horizontal direction of the image.

Thus, any one of claims 1 to 6
In addition to the effect of the item, the image data having an aspect ratio of 3: 4, which is often found in photographing data of a digital camera and display data of a personal computer, without specifying a scaling ratio of the image again, can be converted into 1: 1:
Converted to image data with an aspect ratio of 1.5,
The image can be printed by a photographic printer or the like corresponding to a silver halide photograph having an aspect ratio of 1: 1.5 without any unnaturalness and unnecessary white edges of the image.

Further, the image data having the aspect ratio of 1: 1.5, which is the same as the silver halide photograph, is converted into the image data having the aspect ratio of 3: 4 without specifying the scaling ratio of the image again. Thus, the image data can be transferred to a digital camera or printed by a printer dedicated to the digital camera, and can be displayed on a display of a personal computer without margins.

According to an eighth aspect of the present invention, there is provided an image processing method according to any one of the first to seventh aspects, wherein the coordinate movement amount is calculated by using the pixel of interest and It is characterized in that an exponential function using a term including information on the distance from the reference pixel as an argument is used.

According to the above configuration, in addition to the operation of any one of the first to seventh aspects, by using an exponential function that is a relatively simple expression, the reference pixel of the first digital image data can be obtained. In the periphery, the coordinate movement amount is extremely small, and the movement amount explicit curve in which the rate of increase in the coordinate movement amount itself increases smoothly and rapidly as the distance from the reference pixel increases is accurately expressed.

Thus, any one of claims 1 to 7
In addition to the effect of the term, if the coordinate movement amount is determined based on the movement amount explicit curve at the time of the coordinate conversion process, the image by the coordinate conversion process around the reference pixel which is an important area in the first digital image data. It is possible to obtain smooth and natural second digital image data with almost no distortion.

According to a ninth aspect of the present invention, there is provided an image processing method according to any one of the first to eighth aspects, wherein the second digital image data included in the second digital image data is provided. The method includes a step of performing processing for compensating continuity of image data between pixels.

In the above configuration, the process of compensating for the continuity of the image data is to reduce or eliminate the discontinuity of the second digital image data resulting from moving the first digital image data by the coordinate conversion process. To perform the processing.

As a typical example, a value of a pixel corresponding to a gap position of the second digital image data generated by moving a pixel of the first digital image data in the enlargement direction by the coordinate conversion process is subjected to coordinate conversion. A so-called interpolation process corresponds to calculating and compensating based on the value of the pixel thus obtained.

By moving the pixels of the first digital image data in the reduction direction by the coordinate conversion process,
Instead of performing the pixel thinning process when a plurality of pixels located at different positions in the first digital image data before coordinate conversion overlap as the same pixel in the second digital image data after coordinate conversion, Alternatively, an average value or an intermediate value of a plurality of pixels of the first digital image data and surrounding pixels which are duplicated after the coordinate conversion may be adopted as the pixels of the second digital image data, It is included in the processing for compensating the gender.

According to the above arrangement, in addition to the operation of any one of the first to eighth aspects, the processing for compensating the continuity of the image data between adjacent pixels included in the second digital image data is performed. By doing so, gaps between pixels in the second digital image data after the coordinate conversion are eliminated, and discontinuous changes in adjacent image data are reduced.

Thus, any one of claims 1 to 8 can be provided.
In addition to the effects of the item, even if the first digital image data is subjected to coordinate transformation processing, it is possible to obtain the second digital image data which does not lose the continuity of the image and the smoothness of the color tone change.

According to another aspect of the present invention, there is provided an image processing system comprising: a digital camera for outputting first digital image data; and a first digital image data having a first aspect ratio. Of all the pixels of the first digital image data, a pixel located farther from the reference pixel of the first digital image data has a larger coordinate movement amount, thereby performing a second aspect ratio different from the first aspect ratio. And a printer that obtains the second digital image data, and a printer that prints the second digital image data.

According to the above arrangement, the first digital image data output from the digital camera is subjected to coordinate transformation processing by a computer, so that an area close to the reference pixel, in which the subject intended by the photographer is recorded, is recorded. For, the second digital image having the second aspect ratio suitable for the printer can be obtained while suppressing the image distortion due to the coordinate conversion by reducing the moving amount of the pixel.

This makes it possible to easily print a natural image even in a printer that does not correspond to the aspect ratio of image data of a digital camera, without cutting part of the image data or changing the printer paper size. Become.

According to an eleventh aspect of the present invention, in order to solve the above-mentioned problems, the present invention provides a recording medium, wherein all pixels of the first digital image data having the first aspect ratio are used as reference pixels of the first digital image data. A coordinate conversion step of obtaining second digital image data having a second aspect ratio different from the first aspect ratio by performing a coordinate conversion process in which a pixel at a position farther from the pixel has a larger coordinate shift amount. It is characterized by recording an included image processing program.

According to the above configuration, in the first digital image data having the first aspect ratio, the movement amount of the pixel is small in the area closer to the reference pixel, and the area farther from the reference pixel is subjected to the coordinate conversion processing. It is possible to cause the computer to execute the coordinate conversion processing so that the movement amount of the pixel becomes large.

Accordingly, if a pixel located in an important area in the first digital image data, for example, an area where a subject intended by the photographer is recorded is selected as the reference pixel, image distortion in the important area is suppressed. Meanwhile, the first digital image data is subjected to coordinate conversion processing by the computer.

Thus, even if the aspect ratio of the first digital image data desired to be output does not match the second aspect ratio corresponding to the output device, the computer outputs the entire first digital image data to the computer. By performing the conversion processing, it is possible to obtain second digital image data having a second aspect ratio suitable for output while suppressing image distortion in an important area of the first digital image data.

[0084]

DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described.
The following is a description based on FIG. 1, FIG. 4, and FIG.

The image processing system 1 shown in FIG.
Image of the target, and an aspect ratio of 3: 4 (first as
(Digital image data D)₁(First data
Digital camera 10 for outputting digital image data),
Digital image data D₁With an aspect ratio of 1: 1.5
(Digital image data D having a second aspect ratio)
_Two(2nd digital image data)
Data 20 and digital image data D_TwoDigital to print
Printer 30 (printer).

The computer 20 has a CPU 22 (computer) for executing an image processing program (image processing method) for converting digital image data D ₁ into digital image data D ₂ . The CPU 22 includes the digital camera 1
Input interface unit 2 for data input / output with 0
1 and an output interface unit 26 for inputting and outputting data to and from the digital printer 30. Further, the CPU 22 is interconnected by a bus 25 to a ROM 23 as a read-only memory and a RAM 24 as a random access memory.

The RAM 24 is typically a semiconductor memory or a hard disk built in a computer.
A recording medium that can be separated from the computer main body, for example, a tape medium such as a magnetic tape or a cassette tape, an external magnetic disk such as a floppy disk or a hard disk, an optical disk such as a CD-ROM, or an IC card may be used.

The computer 20 has a user interface unit 27 for providing a user interface. Input / output devices such as a keyboard 27a, a mouse 27b, and a display device 27c are connected to the CPU 22 via the user interface unit 27.

In the image processing system 1, the digital image data D ₁ output from the digital camera 10 is sent to the CPU 22 (computer) via the input interface unit 21.
Is stored in the RAM 24 via the bus 25 once. The stored digital image data D ₁ is C
The digital image data D is read by the PU 22 and subjected to image conversion processing based on an image processing program.
₁ as digital image data D ₂ having a different aspect ratio from the stored in the RAM24 again. CPU 22
The image processing program used for image conversion processing is RAM
24, or may be stored in the ROM 23 if there is no need to change the program. Digital printer 30 in accordance with instructions CPU 22, receives the digital image data D ₂ stored in the RAM24 through the output interface unit 26, for printing.

FIGS. 5A and 5B show digital image data D ₁ output from the digital camera 10 and digital image data D ₂ obtained by converting the digital image data D ₁ by the CPU 22. Here is an example. The aspect ratio of the digital image data D ₁ in FIG. 5 (a) 3: 4 aspect ratio of the digital image data D ₂ in FIG. 5 (b) 1: 1.5.
The digital image data D ₁ and the digital image data D
Each of the _two is composed of a plurality of pixels (not shown).

FIG. 1 shows a schematic flow of the conversion processing program executed by the CPU 22. The conversion processing program includes steps S1 to S7.

First, in step 1 (hereinafter abbreviated as S1), it is checked whether or not the image enlargement / reduction ratio has been set. Here, the scaling ratio of the image, enlarged for obtaining digital image data D ₂ relative to the digital image data D _1, a reduction magnification, magnified digital image data D _1, the direction concept to be reduced Is also included.

[0093] Specifically, the digital image data D ₂ by scaling the digital image data D ₁ in the image longitudinal direction
In the case of obtaining a refers to the ratio of the aspect ratio of the digital image data D ₂ and the aspect ratio of the digital image data D _1, to obtain a digital image data D ₂ by scaling the digital image data D ₁ to the image horizontal direction case, refers to the ratio between the aspect ratio and the aspect ratio of the digital image data D ₂ of the digital image data D _1.

As an example in which the image enlargement / reduction ratio is already set, digital image data D ₁ having an aspect ratio of 3: 4 is converted into digital image data D ₂ having an aspect ratio of 1: 1.5 in advance. There is a case where the enlargement / reduction ratio of the image is set to 9/8 times in the horizontal direction of the image and a fixed value is set.

If it is determined in step S1 that the image enlargement / reduction ratio has not been set, in step S2, the image enlargement / reduction ratio is input from outside the computer 20 via an input device such as the keyboard 27a or mouse 27b or a network. Is received and the input value is stored as a set value in the RAM 24 or the like.

[0096] Incidentally, in S1 and S2, there aspect ratio and the digital image data D _2, the number of the pixel array and the second digital image data, be regarded as a scaling ratio of the broad picture. The like if previously aspect ratio and pixel number sequence of digital image data D ₁ is fixed, from the aspect ratio and pixel arrangement number of the digital image data D _2, uniquely calculate the scaling ratio of the image it is possible, the aspect ratio and the digital image data D _2, is because it is possible to equate the number of the pixel array a second digital image data and scaling ratio of the image.

[0097] Thus, confirm S1 or S2, after the scaling ratio of the image is set at S3, the whether location information do already set to identify the position of the reference pixel in the digital image data D ₁ I do. Here, the positional information indicating the position of the reference pixel may be a specific coordinate values in the coordinate system set in the digital image data D _1, be information for determining the position of the reference pixel uniquely Good.

[0098] Thus, as an example of position information of the reference pixel in the digital image data D ₁ is already set, include the following cases. Advance, since the important object is found to those taken in the central region of the digital image data D _1, digital image data D ₁
If any pixel located within a circular area occupying about 30% of the entire image area from the center of the image is set as a reference pixel, the digital image data D
For the purpose of selecting the pixels constituting the important subject serving figures in _1, it employs a human skin color as a sample color, among the pixel digital image data D _1, with the closest chromaticity according sample color when the above combination information is set to be the reference pixel pixel, that is, among the pixels located inside circular area occupying about 30% of the total image area from the image center of the digital image data D _1, sample color If the position information of the reference pixel in the digital image data D ₁ is determined not to be set in the case S3, it is used as a reference pixel pixel having the closest chromaticity is set to at S4, the computer The input of the position information of the reference pixel is received from outside the device 20 via an input device such as a keyboard 27a or a mouse 27b or a network, and the input information is received. The setting information is stored in the RAM 24 or the like.

[0099] In S5, based on the position information of the scaling factor and the reference pixels set image in S1 to S4, the coordinate moving amount as the target pixel at the position away from the reference pixel of the digital image data D ₁ is increases, and as a result of the coordinate movement, according to scaling ratio of the image, as the aspect ratio of the digital image data D ₁ is changed, the calculation of coordinate movement amount per all the pixels of the digital image data D _1.

For example, when pixels are arranged in a two-dimensional rectangular coordinate system having a vertical axis and a horizontal axis, digital image data D ₁
The closer the pixel is to the reference pixel, the smaller the coordinate shift amount along the vertical and horizontal axes, and the farther away from the reference pixel, the larger the coordinate shift amount along the vertical and horizontal axes. for all pixels of the image data D ₁ and thus performing the calculation of the coordinate movement amount.

[0102] By performing the calculation of the coordinate movement amount having such features, in S6 after, while suppressing deformation or distortion of the image caused by the coordinate moving process around the reference pixel of the digital image data D _1, a digital it is an main object of the present invention to obtain a digital image data D ₂ having an aspect ratio different from the aspect ratio of the image data D _1.

[0102] In S6, according to the coordinate movement amount calculated in S5, by performing coordinate movement of all the pixels of the digital image data D _1, and re-arrangement of the pixel digital image data D _1, digital image data D ₁ obtaining digital image data D ₂ having a different aspect ratio than the.

[0103] That is, the coordinate moving amount of the target pixel calculated in S5 is, if the direction of the value away from the reference pixel along a certain coordinate axis, the image indicated by the digital image data D ₁ expands along the coordinate axis While the coordinate movement is performed,
Coordinate movement amount of the pixel of interest calculated in S5 is, if the direction of the value approaches the reference pixels along the coordinate axis, the coordinate moving to shrink along the coordinate axis image indicated by the digital image data D ₁ is performed Will be.

Specifically, when the aspect ratio of the digital image data D ₁ is larger than the aspect ratio of the digital image data D ₂ , for example, the coordinates of the pixels of the digital image data D ₁ having an aspect ratio of 3: 4 performing movement and rearrangement, 1: in the case of obtaining the digital image data D ₂ having an aspect ratio of 1.5, the whole image of the digital image data D ₁ by the coordinate transformation process, along a horizontal image direction 9 / 8 times or 8 /
It will be reduced by a factor of nine.

[0105] Conversely, when the aspect ratio of the digital image data D ₁ is smaller than the aspect ratio of the digital image data D _2, e.g., 1: coordinates of the pixel digital image data D ₁ having an aspect ratio of 1.5 performing movement and rearrangement, 3: in the case of obtaining the digital image data D ₂ having an aspect ratio of 4, the entire image of the digital image data D ₁ by the coordinate transformation process, along with the image vertical direction 9/8 The image is magnified twice or reduced 8/9 times along the horizontal direction of the image.

However, when the image of the digital image data D ₁ is reduced to obtain the image of the digital image data D ₂ , it becomes necessary to appropriately perform the thinning of the overlapping pixels after the coordinate movement, and the pixel in the digital image data D ₁ since the amount of information is to be reduced by enlarging processing the image of the digital image data D _1, it is preferable to obtain an image of the digital image data D _2.

In rearrangement, for example, if the pixel array of the digital image data D ₂ is to be arranged in a grid,
In the lattice coordinate system set in advance, the pixel of interest may be moved to the lattice position closest to the transformed coordinates of the pixel of interest. The image processing system 1, by performing such pixel shift, the digital printer 30 corresponding to the pixel data of the lattice array, thereby enabling to output accurately digital image data D _2.

[0108] In S7, by performing the processing for compensating the continuity of the image data into digital image data D _2, S6
Reduce the discontinuity of the image data of the digital image data D ₂ resulting from the coordinate movement of the pixel digital image data D ₁ in, eliminated.

Here, as a typical process for compensating the continuity of the image data, the digital image data D ₂ generated by moving the pixels of the digital image data D _{1 in} the image enlargement direction in S 6. The value of the pixel corresponding to the gap position of the digital image data D ₁ whose coordinates have been moved
There is a so-called interpolation process of calculating and compensating based on the pixel value in. For the interpolation processing, an arbitrary method, for example, a nearest neighbor interpolation method, a bilinear interpolation method, a bicubic interpolation method, or the like can be used.

[0110] Further, by coordinate movement of pixels of the digital image data D ₁ at S6 to the image reduction direction, a plurality of pixels that were in different locations in the digital image data D ₁ are the same in the digital image data D ₂ When pixels overlap, digital image data D that overlaps after coordinate conversion is used instead of performing simple pixel thinning processing.
Also to suppress an abrupt change in color tone or brightness of a pixel overlapping portions by employing _one of the plurality of pixels and an average value or an intermediate value, such as the surrounding pixels as a pixel of the digital image data D _2, the digital image data D _It is included in the process of compensating the continuity of the image data of the _second .

[0111] In S7, the process to compensate for the continuity of these image data, by performing the digital image data D ₂ obtained in S6, the image of the digital image data D _2, pixel gaps or color and brightness Such an image is a natural and smooth image without a rapid change.

[0112]

(Embodiment 1) Next, based on FIGS. 5 to 11, the calculation of the coordinate movement amount in S5, the coordinate movement of the pixel in S6, and the processing of compensating the continuity of the image data in S7 will be described. A specific example will be described.

In this embodiment, the digital image data D ₁ having the aspect ratio of 3: 4 shown in FIG.
Is enlarged along the horizontal direction of the image to obtain FIG.
Shown in 1: Consider the case of obtaining the digital image data D ₂ having an aspect ratio of 1.5.

That is, in the present embodiment, the image processing system 1
A digital image data D ₁ having an aspect ratio of 3: 4 output from the digital camera 10
By conversion by 22, the same 1 silver salt photographs: as digital image data D ₂ having an aspect ratio of 1.5, it corresponds to the case of printing by digital printer 30.

[0115] First, the image horizontal direction of the digital image data D _1, i.e. the image longitudinal direction is the X-axis direction, the image vertical direction in the digital image data D _1, i.e. X-axis direction perpendicular to the image transverse direction of the Y-axis direction Is defined. Furthermore, X-axis respectively image the right direction, the image on the direction in the digital image data D _1, the positive direction of the Y-axis, define the lower left corner of the digital image data D ₁ origin, the right end and x = W.

5A and 5B, the image enlargement / reduction ratio R to be determined by the time the image conversion processing shifts to S5 is as follows.
R = (3:
4) / (1: 1.5) = 9/8. Such scaling ratio R
Was input from the keyboard 27a in S2.

[0117] On the other hand, the reference pixels of the digital image data D ₁ is located on the straight line x = W / 2. This is because in FIG. 5A, a person image as an important subject is represented by digital image data D.
_Since the image is located in the central region of the image ₁ , the geometric center of the image of the digital image data D1 is set as the position of the reference pixel before shifting to S3. Therefore, the only parameter externally input in the present embodiment is the image scaling ratio in S2.

[0118] In S5, the calculation of coordinate movement amount of the digital image data D ₁ is performed as follows.

First, a movement amount explicit curve representing the relationship between the coordinate component of the pixel of interest in the X-axis direction and the coordinate movement amount Z of the pixel of interest is defined by Z = F (x). In S6, according to the movement amount explicit curve Z = F (x), if the coordinate component of the target pixel in the X-axis direction is larger than W / 2, Z is set to the right of the image, and the coordinate component of the target pixel in the X-axis direction. Is smaller than W / 2, Z and the pixel of interest are moved to the left of the image.

In general, the function F has a domain 0 ≦ x ≦
W satisfies the following requirements. (1) Z = F (x) is a continuous curve. (2) When the X-axis direction of the coordinate components of the reference pixel is x _0,
F (x ₀ ) becomes the minimum value 0. (3) As the distance between x and x ₀ increases, that is, as the absolute value of the difference between x and x ₀ increases, Z monotonically increases. However, x is in the vicinity of x ₀ , for example, x and x ₀
May be temporarily invariable, or may be a small value such that the rate of increase of Z can be considered to be 0 when the distance between the two is within about 30% of the entire defined area. .

In this embodiment, a specific movement amount explicit curve Z = F (x) is determined by the following procedure.

First, the position change magnification in the X-axis direction of the pixel of interest of the digital image data D _{1 in} the X-axis direction by the coordinate conversion process is set to wk1, and the coordinate component x in the X-axis direction as the position information of the reference pixel set in S3 or S4. _{Using 0} , wk1 is defined by the following (Equation 1). (Number 1) wk1 = b + a × exp [1 - {(x-x 0) / x 0}
ⁿ ] Here, exp represents an exponential function, a and b represent parameter constants, and x and x ₀ represent X of the target pixel and the reference pixel, respectively.
This is the coordinate component in the axial direction. N is a natural number that is a multiple of two.

Using the above wk1, a movement amount explicit curve Z = F (x) representing a specific coordinate movement amount of the pixel of interest is expressed by equation (2). (Equation 2) F (x) = | (wk1-1) × (xx− ₀ ) | where | is an absolute value symbol.

The function F expressed by the equations (1) and (2) satisfies the requirements (1) to (3) such that F (x ₀ ) = 0, and the function of the target pixel and the reference It is represented using an exponential function using a term including information on the distance to the pixel as an argument.

[0125] By such F (x), in the peripheral reference pixels of the digital image data D ₁ coordinate movement amount is extremely small, as the distance from the reference pixel, the ratio itself increases in coordinate movement amount increases smoothly and rapidly The movement amount explicit curve Z = F (x) is accurately represented.

In FIGS. 5 (a) and 5 (b), already mentioned
Thus, the scaling ratio R of the image is (3: 4) /
(1: 1.5) = 9/8, the coordinate component of the reference pixel in the X-axis direction
Minute x ₀= W / 2, use this value
To uniquely determine the parameter constants a and b in Equation (1)
Can be

[0127] That is, as the reference pixel the center of the digital image data D _1, scaling ratio R = 9 / since it is to enlarge 8, the left end of the digital image data D _1, i.e. x wk1 = in = 0 R = 9 / 8, and on a straight line orthogonal to the scaling direction including the reference pixel position, that is, a straight line x
Since the target pixel does not move on = x ₀ = W / 2, wk1 = 1 should be satisfied.

Therefore, the following equations (3) and (4) are derived. (Equation 3) wk1 = b + a = 9/8 (Equation 4) wk1 = b + a × exp (1) = 1 When Equations (3) and (Equation 4) are solved simultaneously, the parameter constants a and b are as follows. Determined by the value. a = 1 / [8 {1-exp (1)}] b = {9 × exp (1) -8} / {8 × exp (1) −
FIG. 6 is a graph obtained by substituting the obtained a and b into Equations (1) and (2) and plotting the obtained movement amount explicit curve Z = F (x) with respect to x.

[0129] That is, in this embodiment, on the basis of the scaling ratio and the reference pixel of the image only the relative position information of the pixel of interest, the amount of movement expressly curve representing the coordinate movement amount for the target pixel of the digital image data D ₁ This means that Z = F (x) is uniquely determined.

[0130] Turning to FIG. 6, as the value of (the number 1) of n increases, F (x) has a small value of the reference pixel peripheral region toward the end portion of the digital image data D _1, It turns out that it becomes large rapidly. That is, (Equation 1)
As the value of n in the equation increases, the tendency that image distortion due to image conversion decreases around the reference pixel and increases as the distance from the reference pixel increases. FIG.
In the image conversion examples shown in (a) and (b), n = 4 is adopted in the expression (Equation 1) in consideration of the naturalness of the obtained image.

The explicit movement amount curve Z = F (x) is expressed by S
Based on the enlargement / reduction ratio of the image set in 1 to S4 and the position information of the reference pixel, the value may be obtained in S5 each time. The same may be used. Further, a plurality of movement amount explicit curves Z = F (x) set in advance may be selected by an operator's instruction or the like.

In the present embodiment, the coordinate movement of the pixel in S6 is performed as follows.

[0133] In S6, performs coordinate transformation on all the pixels of the digital image data D ₁ on the basis of the movement amount explicit curve Z = F (x) determined at S5. Specifically, assuming that the coordinate component in the X-axis direction of the pixel of interest in the digital image data D ₁ is x, and the coordinate component in the X-axis direction of the digital image data D ₂ obtained by performing x coordinate conversion is x ′, Pixel coordinate conversion is performed according to the following equation (5). (Equation 5) x ′ = x−F (x) (x ≦ x ₀ = W / 2) x ′ = x + F (x) (x> x ₀ = W / 2) Thus, the digital image data D ₁ all that to move between all the pixels of the digital image data D ₁ by performing coordinate conversion processing for adjusting the F (x) that indicates the coordinate movement amount corresponding to the coordinate, and moves relative coordinates indicating the position of the pixel of interest by rearranging the pixels, it is possible to obtain a digital image data D _2.

In this embodiment, the pixels of the digital image data D ₁ after the movement are changed so that the digital image data D ₂ corresponding to the pixel data of the lattice-like arrangement can be output accurately from the digital printer 30. The coordinate components in the X-axis direction of the pixel obtained by Expression (5) are appropriately quantized so as to be located on the XY coordinate grid as discrete coordinates at regular intervals.

In this embodiment based on FIG. 5,
Although the digital image data D ₁ having the aspect ratio of 3: 4 shown in FIG. 5A is enlarged in the horizontal direction of the image at a magnification of 9/8 times, the digital image data D ₁ is enlarged in the vertical direction of the image. The digital image data D ₂ having the aspect ratio of 1: 1.5 shown in FIG. 5B can also be obtained by reducing the image data at an enlargement / reduction ratio of 8/9.

In such a case, the coordinate movement of the pixel is performed by changing the X axis in the above description to the Y axis, x to y, x ′ to y ′,
x ₀ may be replaced with y ₀ , and the coordinate transformation may be performed according to Equation (6) using the movement amount explicit curve Z = G (y) for image reduction obtained in the same manner as above. (Equation 6) y ′ = y + G (y) (y ≦ y ₀ ) y ′ = y−G (y) (y> y ₀ ) Next, the processing for compensating the continuity of the image data in S7 of the present embodiment. Will be described with reference to FIG.

[0137] At S6, the digital image data D ₁ by performing the coordinate movement of the pixel in the X-axis direction, has been enlarged converted into digital image data D ₂ having a desired aspect ratio, such enlargement conversion result, Digital image data D ₂
Include so-called gap pixels to which no pixel data is given.

Therefore, in S7, the continuity of the digital image data D ₂ is compensated for by giving a continuous value to the surrounding pixels to the gap pixels of the digital image data D ₂ by interpolation processing.

Digital image data D₁Adjacent to
Pixel P₁, P_TwoCoordinate component in the X-axis direction (hereinafter, this embodiment
, Simply referred to as coordinates)₁, X_TwoWhen
Digital image data after the pixel coordinates are transformed
TA D_TwoPixel P at₁’, P _Two’Coordinates x
₁’, X_Two’.

The interpolation processing referred to here means that the coordinates x ₁ ′, x
Based on the values of the pixels P ₁ ′, P ₂ ′ corresponding to ₂ ′, the coordinates x _i1 ′, x _i2 ′, x between the coordinates x ₁ ′ and x ₂ ′
_{i3 ', ···, x in'} (n = 1 or more integer) pixels P _i1 corresponding to _{', P i2', P i3} ', ···, P in' calculating the value of those decisions to is there. Where P ₁ ′, P ₂ ′ and P
_It is assumed that the coordinate components _in the Y-axis direction of _i1 ', _Pi2 ', _Pi3 ', ..., _Pin ' are all equal.

[0141] Here, at S6, the pixel of the digital image data D ₁ result of coordinate movement in the X-axis direction, on the XY coordinate grid set as discrete coordinates on the digital image data D _2, given pixel data Pixel rows that are not
It is assumed that the gap pixels are arranged in two rows in the axial direction, and the values of the gap pixels P _i1 ′ and P _i2 ′ located on the pixel row are calculated according to the following (Equation 7). ( _Equation 7) V (P _i1 ′) = {2 · V (P ₁ ′) + V (P ₂ ′)} /
3 V (P _i2 ′) = {V (P ₁ ′) + 2 · V (P ₂ ′)} /
3. Here, V (P _x ) indicates the value of the pixel P _x .

[0142] By performing the above interpolation processing, appropriate image data is provided to all pixels of the digital image data D _2. Therefore, so-called gap pixel is eliminated, continuity and naturalness of the digital image data D ₂ of the image is compensated.

FIGS. 8 to 11 show specific image examples obtained by performing the aspect ratio conversion processing based on the above method.

The image shown in FIG. 8 is an original image having an aspect ratio of 3: 4. The image shown in FIG. 9 is obtained by shifting the original image of FIG.
Obtained by enlarging by a factor of / 8:
5 is a converted image having an aspect ratio of 1.5.

In the image of FIG. 9 obtained by such an enlargement conversion, the flower pattern as the image background of FIG. 8 slightly distorts in the horizontal direction of the image, but the flower pattern of the human image located at the center of the image of FIG. Almost no distortion is seen, and even if the aspect ratio is converted by image enlargement processing,
It can be seen that an extremely natural image has been obtained.

On the other hand, the image shown in FIG.
The image shown in FIG. 11 is obtained by reducing the original image of FIG. 10 in the horizontal direction of the image at an enlargement / reduction ratio of 8/9 times while using the image center as a reference pixel. It is a converted image having an aspect ratio of 3: 4.

In the image of FIG. 11 obtained by the above-described reduction conversion, the flower pattern as the image background of FIG. 10 has a slight distortion in the horizontal direction of the image, but the human image located at the center of the image of FIG. Almost no distortion is seen, and it can be seen that an extremely natural image is obtained even when the aspect ratio is converted by the image reduction processing.

In obtaining the image shown in FIG. 11,
The process of compensating the continuity of the image data in S7 is not performed, and the pixel thinning process is performed by adopting the value of the pixel located on the right side in the image of FIG. went.

(Embodiment 2) Next, referring to FIG.
A further specific example of the calculation of the coordinate movement amount in, the coordinate movement of the pixel in S6, and the process of compensating the continuity of the image data in S7 will be described.

In this embodiment, the digital image data D ₁ having the aspect ratio of 1: 1.5 shown in FIG. 12A is enlarged 10/9 times in the horizontal direction of the image, and by expanding to 5/4 along the longitudinal direction, and FIG. 12 (b) to the indicated 3: consider the case of obtaining the digital image data D ₂ having an aspect ratio of 4.

The calculation of the coordinate movement amount in S5 is performed as follows.

First, as in the first embodiment, a digital image
Data D₁The horizontal direction of the image at
Image data D₁The vertical direction of the image at is defined as the Y axis direction.
You. Further, the digital image data D₁To the right of the image
Direction and the image upward direction are the positive directions of the X axis and the Y axis, respectively.
Digital image data D₁The origin is at the lower left corner and x = W at the right end
_x, The upper end is y = W_y(Hereafter, expansion in the X-axis and Y-axis directions)
The parameters and functions that are used most often are appended with X and Y respectively.
Letters to distinguish them).

Therefore, in FIGS. 12 (a) and 12 (b), the scaling ratio of the image to be determined by the time the image conversion process shifts to S5 is as follows: the scaling ratio in the X-axis direction is R _x = 10/9, and the Y-axis The enlargement / reduction ratio in the direction is R _y = 5/4.

FIG. 12A also shows the first embodiment.
In the same way as in
TA D₁S3 or S4
In the digital image data D₁The geometric middle of the image
The heart was set as the position of the reference pixel. In other words, digital images
Data D₁The reference pixel has coordinates (W_x/ 2, W _y
/ 2).

In this embodiment, as in the first embodiment, the explicit movement amount curves Z _x = F _x (x) and Z _y = F _y (y) expressed by the equations (1) and (2). , A movement amount explicit curve representing the relationship between the coordinate component of the pixel of interest in the X-axis direction and the coordinate movement amount Z _x of the pixel of interest, the coordinate component of the pixel of interest in the Y-axis direction, and the coordinate movement amount of the pixel of interest A movement amount explicit curve representing the relationship with Z _y is defined.

In S6, the movement amount explicit curve Z _x
= F _x (x), when the coordinate component of the pixel of interest in the x-axis direction is larger than W _x / 2, Z _{x in} the right direction of the image, and when the coordinate component of the pixel of interest in the x-axis direction is smaller than W _x / 2 Moves Z _x and the pixel of interest in the left direction of the image. Similarly, according to the movement amount explicit curve Z _y = F _y (y), if the coordinate component of the pixel of interest in the y-axis direction is larger than W _y / 2, the coordinate of the pixel of interest in the y-axis direction is Z _y . If the component is smaller than W _y / 2, the pixel of interest is moved by Z _y downward in the image.

Here, the position change magnification in the X-axis direction of the pixel of interest of the digital image data D _{1 in} the X-axis direction by the coordinate conversion processing is wk1, and the position change magnification in the Y-axis direction is wk2.
Then, the following equations (8) to (11) are derived as equations corresponding to equation (3) in the first embodiment. (Number _{8) wk1 = b x + a} x = 10/9 ( number _{9) wk1 = b x + a} x × exp (1) = 1 ( number _{10) wk2 = b y + a} y = 5/4 ( Number 11) wk2 _{= b y + a y × exp} (1) = 1 the equation (8) to a _x = 1 / a (number 9) [9 {1-exp (1 )}] b x = {10 × exp (1 ) -9｝ / ｛9 × exp
(1) -9} and _{a y = 1 / [4 {} 1-exp (1)}] b y = {5 × exp (1) -4} / {4 × exp (1)
-4｝ is determined.

Therefore, the obtained a _x and b _x are expressed by the following _equation (1).
By substituting the equation (2), x amount of movement in the axial direction explicitly curve Z _x = F _{x (x)} is, a _y, a b _y (Equation 1)
By substituting into the equation and the equation (2), the movement amount explicit curve Z _y = F _y (y) in the _y -axis direction is determined. In the image conversion examples shown in FIGS. 12A and 12B, n = 4 in the expression (Equation 1) in consideration of the naturalness of the obtained image.
It was adopted.

In this embodiment, the coordinate movement of the pixel in S6 is performed as follows.

[0160] In S6, the movement amount determined in S5 explicitly curve _{Z x = F x (x)} , performs coordinate conversion for all the pixels of the digital image data D ₁ on the basis of the _{Z y = F y (y)} . Specifically, the coordinates of the pixel of interest in the digital image data D ₁ are (x, y), and the coordinates of the digital image data D ₂ obtained by transforming (x, y) are (x ′, y ′). Then, pixel coordinate conversion is performed according to the following (Equation 12). (Equation 12) x ′ = x−F _x (x) (x ≦ x ₀ = W _x / 2) x ′ = x + F _x (x) (x> x ₀ = W _x / 2) y ′ = y−F _y (y) (y ≦ y ₀ = W _y / 2) y ′ = y + F _y (y) (y> y ₀ = W _y / 2) Thus, the position of the target pixel of the digital image data D ₁ is indicated. Coordinate movement amount F corresponding to the coordinates
To move between all the pixels of the digital image data D ₁ by performing coordinate conversion processing for adjusting the (x), by rearranging all the pixels has moved, it is possible to obtain a digital image data D _2.

Here, similarly to the first embodiment, the digital image data D ₁ after the movement is moved so that the digital image data D ₂ corresponding to the pixel data in the lattice arrangement can be output accurately. So that the pixels are located on an XY coordinate grid, which is discrete coordinates at regular intervals,
The coordinate component of the pixel in the X-axis direction obtained by Expression 5 is appropriately quantized.

As in the present embodiment, the digital image data D
By performing the _first X-axis direction of enlargement or reduction and the digital image data D ₁ Y-axis direction of enlargement or reduction at the same time, as the digital image data D _2, desired not aspect ratio only, a desired number of pixel array digital image data D ₂ having can be obtained. This approach, the digital printer 30 is the number of pixels corresponding array of digital image data is determined to a constant value, particularly advantageous when it is necessary to adjust to a constant value according to the number of the pixel array digital image data D ₂ is there.

In this embodiment, the processing for compensating the continuity of the image data in S7 is performed as follows.

[0164] Results of the pixels of the digital image data D ₁ and coordinate movement in the X-axis direction at S6, the digital image data D ₂
On the XY coordinate grid set as discrete coordinates above,
It is assumed that a pixel to which no pixel data is given occurs in isolation. The value of such a gap pixel P 'compensated by the nearest neighbor interpolation method, by providing a continuous value as the surrounding pixels, is intended to compensate for the continuity of the digital image data D _2.

[0165] The nearest neighbor interpolation method, 'the, gaps pixel P _i' gap pixel P _i that is not given image data by applying one of the values of pixels adjacent to the periphery of the surrounding pixels A method for compensating for continuous values.

Here, in the digital image data D ₂ , out of the eight pixels adjacent to the gap pixel P _i ′, the image data is given and the value of the pixel closest to the reference pixel is calculated as the gap value. It was adopted as the value of the pixel P _i ′. If no image data is given to any of the eight adjacent pixels, the value of the pixel closest to the reference pixel among the 16 pixels further adjacent to the eight adjacent pixels is set as the value of the gap pixel P _i ′. Adopted.

[0167] By performing the above interpolation processing, appropriate image data is provided to all pixels of the digital image data D _2. This eliminates the so-called gap pixels, continuity and naturalness of the digital image data D ₂ of the image is to be compensated.

[0168] As has been described with reference to Examples 1 and 2, the image processing system 1 of FIG. 4, the digital image data D ₁ that is output from the digital camera 10,
CPU22 performs conversion processing based on the step S1 to S7, as digital image data D ₂ less discomfort and has a proper aspect ratio, in which can be printed by the digital printer 30.

[0169]

According to the first aspect of the present invention, there is provided an image processing method comprising:
As described above, for all the pixels of the first digital image data having the first aspect ratio, the coordinate conversion processing in which the coordinate shift amount becomes larger as the pixel is located farther from the reference pixel of the first digital image data. The method includes a coordinate conversion step of obtaining second digital image data having a second aspect ratio different from the first aspect ratio by performing.

Therefore, during the coordinate conversion process, the amount of pixel movement is small in an area near the reference pixel of the first digital image data, and the amount of pixel movement by the coordinate conversion processing is large in an area farther from the reference pixel. And the image distortion due to the coordinate conversion process is suppressed in the important area in the first digital image data where the reference pixel is located.

Accordingly, even if the aspect ratio of the first digital image data desired to be output does not match the corresponding second aspect ratio of the output device, the important area of the first digital image data can be obtained. The first digital image data is entirely converted while the image distortion is suppressed, so that the second digital image data having the second aspect ratio suitable for output can be obtained.

According to a second aspect of the present invention, in the image processing method according to the first aspect, the aspect ratio is converted into the second digital image data based on the first digital image data. In this configuration, a direction is determined, and a coordinate conversion process is performed in which the coordinate shift amount increases as the distance from the reference pixel increases along the direction.

Therefore, in addition to the function of claim 1, the first
In order to perform the coordinate conversion process along the conversion direction of the aspect ratio arbitrarily selected in the digital image data, a straight line including a reference pixel orthogonal to the conversion direction of the aspect ratio;
As the distance from the target pixel increases, the coordinate movement amount by the coordinate conversion process increases.

Thus, in addition to the effect of the first aspect, when the important regions in the first digital image data are distributed in a row like an upright figure, the distribution of the important regions is parallel to the distribution of the important regions. Alternatively, by determining the aspect ratio conversion direction in a direction orthogonal to the direction, the image distortion due to the coordinate conversion processing is less unnatural, and a more natural image can be obtained as the second digital image data.

As described above, in the image processing method according to the third aspect of the present invention, in the configuration of the first or second aspect, the amount of coordinate movement is determined by the scaling ratio of the image and the relative position between the reference pixel and the pixel of interest. The configuration is determined by calculation based on only information.

Therefore, by appropriately selecting a function to be used in the coordinate conversion processing, it is possible to increase the amount of coordinate movement by the coordinate conversion processing in the first digital image data so as to be located farther from the reference pixel in the first digital image data. Can be calculated based only on the enlargement / reduction ratio and relative position information between the reference pixel and the pixel of interest.

Thus, in addition to the effect of the first or second aspect, the number of parameters required for the calculation in the coordinate conversion processing is reduced, and the second digital image data having a desired aspect ratio is obtained simply and at high speed. It has the effect of being able to do so.

According to a fourth aspect of the present invention, in the image processing method according to any one of the first to third aspects, at least one of the image enlargement / reduction ratio and the position information of the reference pixel is input. This is a configuration that includes the step of performing

Therefore, in addition to the function of any one of claims 1 to 3, necessary and sufficient parameters used for calculation for performing the coordinate conversion processing on the first digital image data are appropriately inputted from the outside. You.

Thus, any one of claims 1 to 3 can be provided.
In addition to the effect of the item, the second digital image data having a desired aspect ratio can be obtained by an extremely simple operation of inputting either or both of the image scaling ratio and the reference pixel position information. In addition to this, there is an effect that the set value of the image enlargement / reduction ratio and the position information of the reference pixel can be easily changed from the outside.

According to a fifth aspect of the present invention, in the image processing method according to any one of the first to fourth aspects, the reference pixel is located in a central area of the first digital image data. Pixel.

Therefore, in addition to the function of any one of claims 1 to 4, by setting the reference pixel in the center area of the first digital image data, the center area of the first digital image data can be obtained by the coordinate conversion processing. The image distortion due to coordinate transformation processing such as enlargement becomes larger as the distance from the central region increases.

Thus, any one of claims 1 to 4 can be provided.
In addition to the effect of the term, when it is determined in advance that the main image portion is located in the central region of the first digital image data, the position information of the reference pixel is treated as a variable in the coordinate conversion calculation, Without typing from
It is possible to easily obtain the second digital image data having the desired second aspect ratio while suppressing the image distortion of the important part of the first digital image data.

As described above, according to the image processing method of the invention of claim 6, in the configuration of any one of claims 1 to 5, one of the first aspect ratio and the second aspect ratio is The aspect ratio is the aspect ratio of the display data of the personal computer, and the other is the aspect ratio of the silver halide photograph.

Therefore, in addition to the effects of any one of claims 1 to 5, image data having the same aspect ratio as silver halide photography can be transferred to a digital camera as a natural image, or a printer dedicated to a digital camera can be used. This makes it possible to print on a display of a personal computer without margins.

Further, it is possible to print photographing data of a digital camera, display data of a personal computer, and the like by a photographic printer compatible with silver halide photography without unnatural images and unnecessary white borders. It works.

[0187] According to the image processing method of the present invention, the first aspect ratio is 3: 4 and the second aspect ratio is in the configuration of any one of the first to sixth aspects. Has an aspect ratio of 1: 1.5.

Therefore, in addition to the effects of any one of the first to sixth aspects, without specifying a new image enlargement / reduction ratio, a large amount of data can be used for photographing data of a digital camera or display display data of a personal computer. Image data having an aspect ratio of 3: 4.
The image data can be converted to image data having an aspect ratio of 5 and printed by a photographic printer or the like that supports a silver halide photograph having an aspect ratio of 1: 1.5 without any unnaturalness or extra white edges in the image. This has the effect of being able to do so.

Furthermore, image data having an aspect ratio of 1: 1.5, which is the same as that of silver halide photography, is converted into image data having an aspect ratio of 3: 4 without specifying the enlargement / reduction ratio of the image again. Thus, the image data can be transferred to a digital camera or printed by a printer dedicated to the digital camera, and can be displayed on a display of a personal computer without margins.

The image processing method according to the eighth aspect of the present invention is the image processing method according to any one of the first to seventh aspects, wherein the coordinate movement amount is calculated by using the target pixel and the reference pixel. Is characterized by using an exponential function using a term including the distance information as an argument.

Therefore, in addition to the function of any one of the first to seventh aspects, by using an exponential function which is a relatively simple expression, the coordinate shift around the reference pixel of the first digital image data can be performed. The amount is extremely small, and the movement amount explicit curve in which the rate of increase of the coordinate movement amount itself increases smoothly and rapidly as the distance from the reference pixel increases is accurately expressed.

Thus, any one of claims 1 to 7 can be provided.
In addition to the effect of the term, if the coordinate movement amount is determined based on the movement amount explicit curve at the time of the coordinate conversion process, the image by the coordinate conversion process around the reference pixel which is an important area in the first digital image data. Since almost no distortion occurs,
There is an effect that smooth and natural second digital image data can be obtained.

According to a ninth aspect of the present invention, in the image processing method according to any one of the first to eighth aspects, the image processing method is performed between adjacent pixels included in the second digital image data. The method is characterized by including a step of performing processing for compensating data continuity.

Therefore, in addition to the operation of any one of claims 1 to 8, by performing processing for compensating the continuity of image data between adjacent pixels included in the second digital image data, The gap between the pixels in the second digital image data after the coordinate conversion is eliminated, and the discontinuous change of the adjacent image data is reduced.

Thus, any one of claims 1 to 8 can be provided.
In addition to the effect of the item, even if the first digital image data is subjected to the coordinate transformation processing, the second digital image data which does not lose the continuity of the image and the smoothness of the color tone change can be obtained.

An image processing system according to a tenth aspect of the present invention provides a digital camera that outputs first digital image data and a first camera having a first aspect ratio.
For all the pixels of the digital image data of the first digital image data, a coordinate conversion process is performed such that a pixel located at a position farther from the reference pixel of the first digital image data has a larger coordinate movement amount, thereby obtaining a second pixel image different from the first aspect ratio. It is configured to include a computer that obtains second digital image data having an aspect ratio of 2 and a printer that prints the second digital image data.

Therefore, when the first digital image data output from the digital camera is subjected to the coordinate transformation processing by the computer, the movement of the pixels in the area close to the reference pixel in which the subject intended by the photographer is recorded is described. A second digital image having a second aspect ratio suitable for a printer can be obtained while reducing the amount to suppress image distortion due to coordinate transformation.

Thus, even in a printer that does not support the aspect ratio of image data of a digital camera, a natural image can be easily printed without a partial cut of the image data or a change in the printer paper size. It has the effect of becoming.

According to the eleventh aspect of the present invention, as described above, all the pixels of the first digital image data having the first aspect ratio are separated from the reference pixels of the first digital image data. Is performed by performing a coordinate conversion process in which the coordinate movement amount becomes larger as the pixel is located in the first position.
The image processing program includes a coordinate conversion step of obtaining second digital image data having a second aspect ratio different from the aspect ratio of the image processing.

Therefore, in the first digital image data having the first aspect ratio, the moving amount of the pixel is small in the area closer to the reference pixel, and the moving distance of the pixel by the coordinate conversion process is smaller in the area farther from the reference pixel. It is possible to cause the computer to execute a coordinate conversion process so as to increase the size.

Therefore, if a pixel located in an important area in the first digital image data, for example, an area where a subject intended by the photographer is recorded is selected as the reference pixel, image distortion in the important area is suppressed. Meanwhile, a coordinate conversion process is performed by the computer.

Thus, even if the aspect ratio of the first digital image data desired to be output does not match the corresponding second aspect ratio of the output device, the computer outputs the entire first digital image data to the computer. By performing the conversion process, it is possible to obtain the second digital image data having the second aspect ratio suitable for output while suppressing the image distortion in the important region of the first digital image data. Play.

[Brief description of the drawings]

FIG. 1 is a flowchart showing an outline of a conversion processing program.

FIG. 2A shows 89 mm × 1 on 127 mm paper.
FIG. 7 is an explanatory diagram showing a print area when printing an L size of 27 mm. (B) is 8 on 89 mm paper
FIG. 9 is an explanatory diagram showing a print area when printing an L size of 9 mm × 127 mm.

FIG. 3 is an explanatory diagram of an image conversion process in which image data of a digital camera is uniformly enlarged or reduced in a vertical direction or a horizontal direction of an image so as to have the same aspect ratio as a silver halide photograph.

FIG. 4 is a configuration diagram of an image processing system according to an embodiment of the present invention.

FIG. 5A is an explanatory diagram illustrating an example of digital image data output from a digital camera. (B)
FIG. 3 is an explanatory diagram illustrating an example of digital image data obtained by performing image conversion on the digital image data illustrated in FIG.

FIG. 6 is a movement amount explicit curve Z used for pixel coordinate conversion processing;
FIG. 4 is an explanatory diagram in which = F (x) is plotted.

FIG. 7 is an explanatory diagram of a pixel interpolation process.

FIG. 8 is a photograph showing an example of an image having an aspect ratio of 3: 4.

FIG. 9 is a photograph showing an image having an aspect ratio of 1: 1.5 obtained by enlarging the image shown in the photograph of FIG. 8;

FIG. 10 is a photograph showing an example of an image having an aspect ratio of 1: 1.5.

11 is a photograph showing an image having an aspect ratio of 3: 4 obtained by reducing the image shown in the photograph of FIG. 10;

FIG. 12A is an explanatory diagram illustrating a further example of digital image data output from a digital camera.
FIG. 3B is an explanatory diagram illustrating an example of digital image data obtained by performing image conversion on the digital image data illustrated in FIG.

[Explanation of symbols]

 1 Image Processing System 10 Digital Camera 20 Computer 21 Input Interface Unit 22 CPU (Computer) 23 ROM 24 RAM 25 Bus 26 Output Interface Unit 27 User Interface Unit 27a Keyboard 27b Mouse 27c Display Device 30 Digital Printer

Claims (11)

[Claims] 1. A coordinate conversion process in which, for all pixels of a first digital image data having a first aspect ratio, a pixel located at a position farther from a reference pixel of the first digital image data has a larger coordinate movement amount. An image processing method comprising: performing a coordinate conversion step of obtaining second digital image data having a second aspect ratio different from the first aspect ratio. 2. A conversion direction of an aspect ratio to the second digital image data is determined based on the first digital image data, and a coordinate shift amount increases as a pixel moves further away from the reference pixel along the direction. The image processing method according to claim 1, wherein the following coordinate conversion processing is performed. 3. The image according to claim 1, wherein the coordinate movement amount is determined by a calculation based on only an enlargement / reduction ratio of the image and relative position information between the reference pixel and the pixel of interest. Processing method. 4. The image processing method according to claim 1, further comprising the step of inputting at least one of an image scaling ratio and position information of said reference pixel. 5. The image processing method according to claim 1, wherein the reference pixel is a pixel located in a central area of the first digital image data. 6. One of the first aspect ratio and the second aspect ratio is an aspect ratio of display display data of a personal computer, and the other is an aspect ratio of a silver halide photograph. The image processing method according to claim 1. 7. One of the first aspect ratio and the second aspect ratio is 3: 4, and the other is 1: 1.5.
The image processing method according to claim 1, wherein: 8. The method according to claim 1, wherein the coordinate movement amount is calculated using an exponential function having a term including a distance information between the target pixel and the reference pixel as an argument. The image processing method according to 1. 9. The method according to claim 1, further comprising the step of performing processing for compensating for continuity of image data between adjacent pixels included in said second digital image data. The image processing method according to 1. 10. A digital camera for outputting first digital image data, wherein all the pixels of the first digital image data having a first aspect ratio are located at positions distant from the reference pixels of the first digital image data. A computer that obtains second digital image data having a second aspect ratio different from the first aspect ratio by performing a coordinate conversion process in which a certain pixel has a larger coordinate movement amount; and a second digital image. An image processing system, comprising: a printer for printing data. 11. A coordinate conversion process for all pixels of the first digital image data having the first aspect ratio, in which a pixel located farther from a reference pixel of the first digital image data has a larger coordinate shift amount. A recording medium on which is recorded an image processing program including a coordinate conversion step of obtaining second digital image data having a second aspect ratio different from the first aspect ratio by performing.